What is the gold standard treatment for triple negative high-grade ductal carcinoma in situ (DCIS)?

From the Guidelines

The gold standard treatment for triple negative high-grade ductal carcinoma in situ (DCIS) is surgical excision, either through breast-conserving surgery (lumpectomy) followed by radiation therapy or mastectomy, as stated in the most recent guideline by the European Society for Medical Oncology (ESMO) 1.

Key Considerations

• The goal of treatment is to completely remove the abnormal cells before they have the opportunity to become invasive, as triple negative DCIS has a higher risk of recurrence and progression to invasive cancer compared to hormone receptor-positive DCIS.
• For lumpectomy, the goal is to remove the DCIS with clear surgical margins (typically at least 2mm), followed by whole breast radiation therapy to reduce the risk of local recurrence.
• Mastectomy may be recommended for extensive DCIS, multicentric disease, or when clear margins cannot be achieved with lumpectomy.

Treatment Approach

• Unlike invasive triple negative breast cancer, DCIS does not require chemotherapy as standard treatment since it is a non-invasive condition confined within the milk ducts without spread to surrounding tissues.
• Hormonal therapy is not beneficial for triple negative DCIS since it lacks estrogen, progesterone, and HER2 receptors.
• Regular follow-up with clinical breast exams and imaging is essential after treatment.

Radiation Therapy

• Whole breast radiation therapy (WBRT) after breast-conserving surgery (BCS) for DCIS halves the risk of local recurrence without impact on survival, as noted in the ESMO guideline 1.
• Hypofractionated regimens can be used instead of longer treatment schedules, and the addition of a boost dose to the primary tumour bed lowers recurrence rates in intermediate- to high-risk patients.

Additional Considerations

• The treatment approach should be individualized based on the patient's age, body habitus, general health status, and preferences, as well as the tumour extent and location, as outlined in the ESMO guideline 1.
• The possibility of hereditary cancer should be explored, and prophylactic procedures discussed if necessary, following appropriate genetic counselling and testing of the patient.

From the Research

Treatment Options for Triple Negative High-Grade DCIS

The treatment for triple negative high-grade ductal carcinoma in situ (DCIS) is a subject of ongoing research and debate. Based on the available evidence, the following treatment options are considered:

• Surgery: Wide excision or mastectomy are the primary surgical options for DCIS 2, 3, 4, 5, 6.
• Radiotherapy: Radiotherapy is effective in reducing the risk of local recurrence, especially in patients with high-grade tumors or those with close or positive surgical margins 2, 3, 4, 5.
• Breast-Conserving Therapy: Breast-conserving therapy, which includes wide excision followed by radiotherapy, is a suitable option for most patients with DCIS 3, 4, 5.

Factors Influencing Treatment Decisions

The following factors influence treatment decisions for triple negative high-grade DCIS:

• Tumor size and grade: Patients with smaller, low-grade tumors may be suitable for breast-conserving therapy without radiotherapy, while those with larger, high-grade tumors may require mastectomy or radiotherapy 2, 3, 6.
• Surgical margins: Clear surgical margins are essential to reduce the risk of local recurrence 2, 3, 4, 5, 6.
• Patient preferences: Patient preferences and values play a significant role in treatment decisions, and patients should be fully informed about the risks and benefits of each treatment option 3, 5.

Controversies and Future Directions

There are ongoing controversies and debates in the management of DCIS, including:

• Role of tamoxifen: The use of tamoxifen in the treatment of DCIS is controversial, and its effectiveness in reducing the risk of recurrence is still being studied 4, 5.
• Minimally invasive treatments: The role of minimally invasive treatments, such as radiofrequency ablation and cryotherapy, in the management of DCIS is still being investigated 4.
• Predictive factors: Research is ongoing to identify predictive factors that can help identify patients at high risk of recurrence and those who may benefit from more aggressive treatment 5.